Demineralized bone matrix (DBM) refers to a bone whose minerals have been removed by adding it to an acid. Demineralized bone matrix mostly consists of highly cross-linked collagen and comprises the remaining non-collagenic proteins such as TGF-β, PDGF, osteopontin, osteonectin, bone morphogenetic protein (BMP) and the like. Demineralized bone matrix is used in a composition for bone implants, in the repair of bone defects, etc.
Demineralized bone matrix is obtained in a particulate form, through demineralizing a bone externally discharged from a body, followed by pulverizing into an appropriate size. The present inventors have disclosed a bone-repair composition comprising a demineralized bone matrix having a particle size of 0.05 to 250 μm; a demineralized bone matrix having a particle size of 250 to 2000 μm; and a hydrating material, wherein the demineralized bone matrixes are mixed in a certain ratio. The bone-repair composition has excellent injectability and shape-maintenance (handling) properties (Korean Patent No. 10-1041784).
Meanwhile, cortical bone consists of collagen fiber bundles that are oriented parallel to the long axis thereof. It is known that the fibrous demineralized bone matrix obtained therefrom exhibits properties useful for implants intended for use in bone repairs and other orthopedic applications. The fibrous demineralized bone matrix is prepared by milling a cortical bone externally discharged from a body with a special milling machinery until a particle having a fiber form is obtained, followed by demineralizing the resulting particles (U.S. Pat. No. 5,607,269). However, there are some drawbacks, e.g., that such a method needs to use only intact cortical shafts as a bone source, because of the mechanical limitations of the bone milling machinery; and that the yield of the fibrous demineralized bone is very low. In order to address said problems, U.S. Pat. Nos. 7,323,193 and 7,939,108 have disclosed a process for preparing a fibrous demineralized bone matrix, comprising demineralizing the bone sections obtained from a bone externally discharged from a body in an acidic solution for 6 hours, demineralizing the resultant in an acidic solution for two days, and then pulverizing the demineralized bone sections. However, the processes disclosed in U.S. Pat. Nos. 7,323,193 and 7,939,108 have a drawback that the demineralizing step needs to be performed for long time, i.e., for two days (48 hours).